A combination of anatomical, histochemical and physiological methods were utilized to investigate the synaptic organization of ninth and tenth sympathetic ganglia of bullfrogs. Intracellular recording reveals that preganglionic B fibers in the sympathetic chain connect to B cells and generate a slow EPSP. Furthermore, preganglionic C fibers in the eighth nerve connect to C cells and generate a slow IPSP. The cholinergic preganglionic fiber stains for acetylcholinesterase and was observed in the light and electron microscope to spiral around the axon hillock of the ganglion cell before arborizing and synapsing on the soma. Most synapses were located on the soma near the axon hillock region with electron microscopic features typical for cholinergic junctions. Fluorescent (SIF) cells in the ganglia. SIF cells stain positively for the chromaffin reaction and in the electron microscope appear to be identical with chromaffin cells in the adrenal.